iPhone/iPod Touch Application Codes/Designers

Hi there, I am looking for people who are capable of producing applications for the iphone/ipod touch. I would like to see examples of previous work and am looking to work with people who have had previous apps accepted on the itunes apps store. At the moment I am also interested in finding out how much you would charge to create a very simple app: for now lets just say a basic app that can add, subtract, multiply and divide numbers. Many thanks - I look forward to hearing from you.